1. Technical Field
Embodiments disclosed herein relate to speakers and methods of making speakers, and more specifically, to methods of making speakers that may be configured to be integrated into a roll-to-roll manufacturing process.
2. Description of Related Art
Visual and acoustic means are two effective ways of communication. As a result, scientists and engineers have continued to develop components and systems for visual or acoustic applications. One acoustic application may include the use of speakers, including electro-acoustic speakers. Electro-acoustic speakers may be categorized as direct and indirect radiant speakers. Generally, speakers can also be roughly categorized, based on their operating theories, into dynamic speakers, piezoelectric speakers and electrostatic speakers. Dynamic or magnetic-membrane speakers have been frequently used because of their well-developed technologies and have dominated the speaker market. However, dynamic or magnetic-membrane speakers may have disadvantages due to their large sizes, making them less desirable for portable or smaller-sized consumer products or for other applications that have space constraints.
In contrast, piezoelectric speakers operate based on the piezoelectric effects of piezoelectric materials and rely on the application of electrical fields to piezoelectric materials to drive sound-producing diaphragms or membranes. Piezoelectric speakers generally require less space and may have thin or planar designs. However, piezoelectric materials formed by sintering processes may be rigid and inflexible.
Additionally, electrostatic speakers are generally designed with two fixed electrode-plates having holes and a conductive membrane between the two plates for forming a capacitor. A DC voltage bias may be applied to the membrane, and an AC voltage may be applied to the two electrodes. The electrostatic force generated by the positive and negative fields may drive the conductive membrane to generate sound.
Moreover, efforts have been made to combine visual and acoustic applications. For example, a holographic transparent speaker as disclosed in U.S. Pat. No. 6,199,655 is an electrostatic speaker with the diaphragm made of Mylar or Kapton. This speaker is characterized in that the holes opened in the bi-layer transparent electrode plate are arranged in an interlaced manner, so as to generate a holographic visual effect. However, the above speaker may not produce an image effect, nor achieve a lighting effect in a dark environment for lack of an active light source module.